Gov. Jerry Brown holds up a chart showing the statewide average precipitation by water year while declaring a drought state of emergency while speaking in San Francisco, Friday, Jan. 17, 2014. With a record-dry year, reservoir levels under strain and no rain in the forecast, California Gov. Jerry Brown formally proclaimed the state in a drought Friday, confirming what many already knew. Brown made the announcement in San Francisco amid increasing pressure in recent weeks from the state's lawmakers, including Democratic Sen. Dianne Feinstein. (AP Photo/Jeff Chiu)

LOS ANGELES (AP) — Government in drought-afflicted California is trying to lead by example and cut water use by the same 20 percent that residents have been asked to save.

While the cuts are not mandatory, some state agencies already have proposed measures that could save billions of gallons of water this year.

The biggest savings would come from landscaping.

The state Department of Transportation says it can save half of the water it has been using to irrigate 30,000 acres throughout the state, principally highway vegetation.

That translates into 6 billion gallons a year of water savings — more than enough to fill a swimming pool that is 10 feet deep, one mile wide and two miles long.

Another way of looking at it: Those savings alone would be about as much water as a city of 30,000 people uses in a year, according to Caltrans spokeswoman Tamie McGowen.

There is also a moratorium on new landscaping on state property and along state roads, unless the project is deemed essential.

Elsewhere, changes are largely symbolic.

Decorative fountains at some state properties have been drained, including the rose garden on the grounds of the state Capitol. State vehicles, from fire engines to cars, will get washed only when it rains — unless a scrub down is needed for health or safety reasons.

“In some cases, you’re talking about a couple of buckets,” said Brian Ferguson of the Department of General Services, which is coordinating the government efforts to wean itself of water. Even so, he said, the message should be clear: Business as usual has to change.

Every drop helps in a state where officials say 2013 was the driest calendar year on record. Rains this week are nowhere near enough to make up the deficit.

When Gov. Jerry Brown declared a drought on Jan. 17, he urged California residents to cut back water use by 20 percent. He also said state agencies would cut back, though the declaration didn’t specify how much.

Under an existing executive order, state agencies already were supposed to reduce water use 10 percent by 2015. Now the Department of General Services is counseling that the new goal be at least 20 percent.

The reduction is not mandatory partly because some water use cannot be reduced without long-term consequences, said Ferguson, citing as an example bushes in highway medians that help reduce the severity of accidents.